Vehicle lift installation

ABSTRACT

Open areas of the floor pit of a vehicle lift installation are covered by a first pair of cover plates when the lift is lowered and by a second pair of cover plates when the lift is raised. The first pair of cover plates are spread open by the lift superstructure or jacking unit and the second pair of cover plates are moved to a closed position by motion transmitting means connecting them to the first pair of cover plates. In one embodiment the motion transmitting means interconnecting the two pairs of cover plates includes a lost motion linkage and the pivot axes for the two pairs of cover plates are offset whereby the second pair of cover plates pivots through a greater angle than the first pair of cover plates. In the second embodiment the plates forming the two pairs of cover plates are interconnected by combined hinge and motion transmitting devices and both pairs of cover plates are pivoted through substantially 90*.

United States Patent 2,594,892 4/1952 Estel.... l87/8.62 2,655,224 10/1953 l-lott.... l87/8.62 3,393,772 7/1968 Pelouch........................ l87/8.62

Primary Examiner-Harvey C. Hornsby ABSTRACT: Open areas of the floor pit of a vehicle lift installation are covered by a first pair of cover plates when the lift is lowered and by a second pair of cover plates when the lift is raised. The first pair of cover plates are spread open by the lift Inventor Martin J. Sherry Dayton, Ohio 846,009

Filed July 30, 1969 Patented Sept. 28, 1971 Assignee The Joyce-Cridland Company Dayton, Ohio VEHICLE LIFT INSTALLATION 27 Claims, I0 Drawing Figs.

[21] AppLNo.

superstructure or jacking unit and the second pair of cover plates are moved to a closed position by motion transmitting means connecting them to the first pair of cover plates.

In one embodiment the motion transmitting means interconnecting the two pairs of cover plates includes a lost motion s 2 4 m4tlm u 7 67 2 8 8 m NW4 WW mm3- mu" NW4 "9 mu m "m m u .3 H n m m m "N2 m W m wa I he m cm k U I F H N 5 55 .1 [l

374 linkage and the pivot axes for the two pairs of cover plates are offset whereby the second pair of cover plates pivots through a References Cited UNITED STATES PATENTS greater angle than the first pair of cover plates. In the second embodiment the plates forming the two pairs of cover plates 49/68 are interconnected by combined hinge and motion trans- 49/68 mitting devices and both pairs of cover plates are pivoted l87/8.62 through substantially 90.

1,005,535 Gillespie. 4/1933 Wood...... 4/1952 Smith PATENIED SEP28 an SHEET 1 OF 2 INVENTOR. MART/N J. SHERRY HIS ATTORNEYS SHEEI 2 [IF 2 PATENTEUsEmmn 3608.675

INVENTOR. MART/N J SHERRY BY a 7' HIS A TTORNEYS VEHICLE LIFT INSTALLATION This invention relates to vehicle lift installations and more particularly to apparatus for covering the floor pit of a vehicle lift installation.

Vehicle lift installations of the type having lift members received within a floor pit when the lift is lowered are, for purposes of safety, covered by plates pivotally mounted on the margins of the pit. The cover plates conventionally are engaged by the lift members as the lift is raised and pivoted out of their pit covering positions, leaving the pit uncovered when the lift is raised. The potential hazards of the uncovered floor pit are apparent. There have been suggestions to provide mechanisms to cover lift floor pits when the lift is raised but, apparently due to their complexity and excessive cost, they are not commercially available.

An object of this invention is to provide a cover plate construction for a vehicle lift installation which substantially covers the floor pit both when the lift is lowered and when the lift is raised and to provide such a pit cover assembly which is inexpensive and easy to install.

In accordance with this invention, two pairs of pit cover plates are pivotally mounted on opposite side margins of the floor pit. One pair, termed the main cover plates" herein, covers open areas of the pit when the lift is lowered. As the lift is raised, the main cover plates are pivoted out of their pit covering positions. The other pair of cover plates, termedthe auxiliary cover plates," are located in the pit below the main cover plates when the lift is lowered and are pivoted to a pitcovering position when the lift is raised.

Another object of this invention is to provide such a cover plate construction which ordinarily responds to movement of the lift parts housed within the pit when the lift is lowered. In accordance with this invention, the main cover plates are engaged by the lift superstructure and jacking unit as the lift is raised and thereby pivoted to a raised position. The auxiliary cover plates are connected to the main cover plates by motion-transmitting means whereupon the auxiliary cover plates pivot in response to pivotal movement of the main cover plates. When raised, the cover plates are off center with respect to their pivot points so that the main cover plates rest against the lift-jacking unit. When the lift is lowered, the offcenter weights of the cover plates cause the main cover plates to pivot to pit covering positions by the operation of gravity. Accordingly, the cover plate construction of this invention is so designed that the floor pit is automatically covered at substantially all times.

It is another object of this invention to provide such a cover plate construction which can be embodied in a vehicle lift installation with little or no increase in'the size of the floor pit and which does not interfere with the normal operation of the vehicle lift. The main cover plates pivot from a position substantially flush with floor level to a generally vertical position and, accordingly, do not require space in the floor pit. The auxiliary plates are housed within the floor pit when the lift is lowered but, in accordance with this invention, they lie closely adjacent the side walls of the floor pit when the lift is lowered and, hence, occupy very little space therein. Further, the edges of the auxiliary cover plates remote from the side margins of the floor pit are recessed or cut away as required to avoid contact with the other parts of the lift located within the floor pit.

In one embodiment of this invention the main cover plates rest against the lift jacking unit in a tilted position at an acute angle to the floor when the lift is elevated. Since the auxiliary cover plates are substantially flush with floor level at this time, there is an acute angle between each main cover plate and its associated auxiliary cover plate. To locate the auxiliary cover plates in a vertical position adjacent the pit sidewalls when the lift is lowered, it is apparent that the angular relationship between the main cover plates and the auxiliary cover plates must change as the lift lowers. To obtain this change in angular relationship, the auxiliary cover plates pivot about axes parallel to but offset from the pivot axes of the main cover plates, the pivot axes of the auxiliary cover plates being spaced more closely and vertically lower than the pivot axes of the main cover plates. Also, each main cover plate is connected to its associated auxiliary cover plate by hinged, sliding link assemblies which accommodate the changes in the angular positions of the two sets of cover plates.

In another embodiment of this invention both the main cover plates and the auxiliary cover plates pivot through angles of substantially and the two sets of plates are both connected to elongate hinge members. Because of this construction, a novel simple and inexpensive hinge construction is used. The main cover plates are caused to rotate through 90 by means of bearing members forming part thereof adapted to engage the lift-jacking unit. The bearing members are sufficiently long that the main cover plates are held in a vertical position when the lift is raised.

Other objects and advantages will become apparent from the following description and the drawings in which:

FIG. 1 is a perspective view of a vehicle lift installation made in accordance with this invention;

FIG. 2 is a cross-sectional view of the installation of FIG. I as viewed in the direction of arrows 2-2 thereof. In both FIGS. 1 and 2, the usual pit cover plates are shown elevated and the auxiliary cover plates in their pit covering positions;

FIG. 3 is a cross-sectional view of a portion of the installation of FIG. 1 showing the position of parts of the cover assembly as they would be when the lift is lowered into the floor P FIG. 4 is an enlarged cross-sectional view of a portion of the lift installation within the view line 4 of FIG. 2;

FIG. 5 is a perspective view of another embodiment of a vehicle lift installation made in accordance with this invention illustrating a different type of lift superstructure from that shown in FIG. I and another embodiment of a cover plate construction;

FIG. 6 is a plan view of the pit cover plate construction of FIG. 4 and showing the lift ram and a nonrotating tube in cross section when the lift is elevated;

FIG. 7 is a plan view of a portion of the lift installation of FIG. 5 when the lift is lowered;

FIGS. 8 and 9 are cross-sectional views of portions of the lift installation of FIG. 5 as viewed in the direction of arrows 8-8 and 9-9, respectively, in FIG. 6; and

FIG. 10 is a cross-sectional view taken in the direction of arrows 10-10 ofFIG. 7.

Referring in greater detail to FIG. I, a vehicle lift installation in accordance with this invention is generally designated 10 and comprises a vehicle lift generally designated 12 of the type having ajacking unit including a lift cylinder 14 and a lift piston or ram 16. For purposes of illustration the lift 12 is shown as having a superstructure of the type including an elongate lift beam or rail 18 connected at its midportion to the top of the lift ram 16 by bolts 20. Mounted on the opposite ends of the rail 18 are vertically oriented plates 22 which in turn support bolster plates 24 on each of which are pivotally mounted a pair of vehicle engaging swing arms 26. The vehicle lift 12 is of the type adapted to lift vehicles which are driven thereover, the swing arms 26 then being pivoted to positions appropriate to engage the vehicle frame. Ordinarily, lifts of this type are provided with pads (not shown) mounted on slides such as those partially illustrated at 28. Rotation of the lift superstructure and the lift ram 16 is prevented by a conventional telescopic nonrotating tube 30 connected by a bolt 32 to the rail 18. The lift ram 16 may be moved vertically up and down by conventional hydraulic or semihydraulic operation.

The lift installation 10 further includes a floor pit, generally designated 34, of a rectangular, boxlike construction open at its upper end. When the lift 12 is lowered, the ram 16, tube 30 and the beam 18 are received in the floor pit 34. The vertically oriented plates 22 lie along the ends of the floor pit 34 with the bolster plates 24 and the swing arms 26 lying at the level of the surrounding floor F in covering relation to the ends of the pit 34. For purposes of safety, the otherwise open top of the floor pit 34 intermediate the bolster plates 24 is covered by a pair of elongate, rectangular main pit cover plates 36 and 38 hinged as indicated at 40 and 42, respectively, to the opposite longer, upper margins 44 and 46, respectively, of the floor pit 34. As shown in FIG. 3, the edges of the cover plates 36 and 38 remote from the upper margins 44 and 46, when the lift is lowered, are in confronting relation and approximately level with the surrounding floor F. In their lower, pit-covering positions, the cover plates 36 and 38 derive support from vertical support posts 48 which may be threaded through adapters 50 (FIG. I) mounted on channels or the like 52 in the bottom of the floor pit 34. The lift rail 18 is apertured as indicated at 54 to receive the support post 48 as the superstructure is lowered.

The pit cover plates 36 and 38 illustrated in the drawings are provided on the underside thereof with longitudinally extending channels 56 and 58, respectively, which are used for additional strength. The cover plates 36 and 38 further include a pair of lift engaging cam or bearing members 60 and 62, respectively, mounted in this case on the lower surface of the channels 56 and 58. When the lift 12 is raised the cams or bearings 60 and 62 rest on the lift ram 16. To prevent scarring of the lift ram 16, the members 60 and 62 are preferably made from a relatively soft metal.

The main cover plates 36 and 38 are pivoted to their tilted, generally vertical positions shown in FIGS. 1 and 2 by movement of the lift 12. In its upward movement, the lift rail 18 strikes the free edges of the cover plates 36 and 38 lifting these free edges until the earns 60 and 62 rest against the lift ram 16. When raised, the center of mass of the plates 36 and 38 is inside the margins of the pit 34 and the plates 36 and 38 lie at a stable, acute angle to the horizontal. When the lift 12 is lowered, the cover plates 36 and 38 fall by gravity back into the position shown in FIG. 3. Wedge-shaped or beveled cam members 64 mounted on top of the lift rail 18 guide the plates 36 and 38 as they slide therealong.

Referring to FIGS. 1 and 4, the upper rectangular margins of the pit 34 are bounded by angle members 66, one leg of each being flush with the level of the floor F and the other leg of each depending substantially flush with the inside surfaces of the floor pit 34. The aforementioned hinges 40 and 42 can conveniently be made from inverted J-shaped metal hinge straps 68, the bight portions of which receive hinge pins 70 welded to the plates 36 and 38. Before installation of the floor pit 34, the inverted .I-shaped hinge straps 68 can conveniently be connected by bolt fasteners 72 to the exposed face of the depending legs of the longer angle members 66 in the manner illustrated in FIGS. 3 and 4. The short legs of the bights are contiguous to the upper leg of the associated angle members 66 in order to confine the hinge pins 70. For ease of installation, side and end panels 74 made from sheet metal may be welded to the angle members 66. The assembly of the members 66 and the side and end panels 74 with the hinges 40 and 42 already formed thereon are used as a form around which the concrete for the surrounding floor is poured.

During normal use the rail 18 extends transversely of the vehicle to be raised and approximately midway the length of the vehicle. Mechanics working on the underside of the vehicle find it convenient to use the rail 18 for tools and will often be working close to the area of the floor pit 34. The possibility of a tool falling into the floor pit 34 and the hazards to the safety of the mechanics are apparent if the floor pit 34 is left open when the lift 12 is elevated. In accordance with this invention the floor pit 34 is covered when the lift 12 is elevated by an auxiliary cover structure comprising a pair of elongate, rectangular auxiliary cover plates 76 and 78 which are pivotally connected to the same margins 44 and 46 of the pit 34 as are the main cover plates 36 and 38, respectively. The pivotal mounting of the auxiliary cover plates 76 and 78 may be substantially the same as the hinge constructions 40 and 42. Thus, inverted .l-shaped hinge straps 80 are mounted by other bolt fasteners 72 to the exposed depending face of the angle member 66. The hinge straps 80 receive hinge pins 82 that are welded to the undersides of the associated auxiliary cover plates 76 and 78. For reasons described below, the axes of the hinge pins 82 are vertically lower than, and horizontally inwardly of, the axes of the hinge pins 70 for the main cover plates 36 and 38.

The auxiliary cover plates are designed automatically to cover the floor pit 34 as the lift 12 is being raised. In accordance with this invention, the auxiliary cover plates 76 and 78 are connected to the main cover plates 36 and 38 by motion transmitting means comprising adjustable link assemblies generally designated 84. Preferably there are at least two adjustable link assemblies 84 for each main cover plate 36 and 38 and their auxiliary cover plates 76 and 78. Each of the adjustable link assemblies 84 comprises a first hinge assembly 86 having a first hinge plate 88 affixed to the underside of its associated main cover plate 36, 38 and a second hinge plate 90 which pivots about a hinge pin 92 located in the hinge barrel formed by the two plates 88 and 90. Each adjustable link assembly 84 further includes a second hinge assembly 94 having a first hinge plate 96 affixed to the top surface of the associated auxiliary cover plate 76, 78 and a second hinge plate 98 which is pivotal about a hinge pin 100 located in the barrel formed by the two plates 96 and 98. Referring to FIG. 2, the main cover plate 36 illustrated therein is connected to its associated auxiliary cover plate 76 by a threaded connector pin 102 that is slidably received by an aperture in a flange 104 on the hinge plate 90 and threadedly received by an aperture in flange 106 on the hinge plate 98. The main cover plate 38 is identically connected to its associated auxiliary cover plate 78.

With the adjustable link assemblies 84 assembled, the auxiliary cover plates 76 and 78 will pivot with their associated main cover plates 36 and 38, respectively. The pivot axes of the plates 76 and 78 are spaced closer together than the pivot axes of the main cover plates 36 and 38 so that the auxiliary cover plates will pivot through a greater angle than the main cover plates 36 and 38. Because the pivot axes of the auxiliary plates 76 and 78 are lower than and spaced inside of the pivot axes of the main cover plates 36 and 38, the greatest angle between the two sets of plates occurs when the lift is lowered and the cover plates occupy the positions thereof shown in FIG. 3. It will be noted in FIG. 3 that the angle between the cover plate 38 and the auxiliary cover plate 78 is nearly 90. Therefore there is ample clearance for the lower portions of the lift superstructure within the pit 34 and between the lowered auxiliary cover plate 76 and 78. When the lift i2 is raised as shown in FIG. 2, the included angles between the main cover plates and the auxiliary cover plates is significantly less than 90. However, the cover plates 76 and 78 are still flush with floor level because of the different pivot axes provided for the two sets of plates. The change in the angular relation between the two sets of cover plates is accommodated by the adjustable link assemblies 84. As perhaps best understood by a comparison of the link assembly 84 shown in FIG. 3 with that shown in FIG. 2, the sliding relation between the pins 102 and the flanges 104 of the hinge assemblies connected to the main cover plates results in a lost motion when the main cover plates 36 and 38 are begun to be raised.

When the lift installation 10 is initially constructed, the lift ram 16 is elevated to raise the cover plates 36 and 38. The adjustable link assemblies 84 are then adjusted by rotation of the adjusting pins 102 as needed to bring the auxiliary cover plates 76 and 78 into locations coplanar with one another and substantially flush with the level of the surrounding floor. Some adjustment of the adjustable link assemblies 84 will normally be required for this purpose because the jacking unit, consisting of the cylinder 14 and the ram 16, is rarely precisely centered within the lift pit 34. Ordinarily, once the adjustment has been made, no further adjustment will be necessary. Should the cam or bearing member 60 or 62 become worn from repeated usage, the proper angle between the two sets of cover plates can again be obtained by another adjustment of the adjustable link assemblies 84 following the procedures described immediately above.

The main cover plates 36 and 38 cover only the open area of the pit 34 remaining uncovered by the bolster plates 24. For this purpose, each main cover plate has approximately onehalf the width of the pit 34 and a length only slightly less than the separation between the bolster plates 24. As well known, in some lift installations having floor pits the entire superstructure supported by the lift ram is received in the floor pit. In such cases, of course, the cover plates 36 and 38 would extend the entire length and together would extend the entire width of the floor pit. in any event the auxiliary cover plates 76 and 78 preferably cover substantially the entire width and length of the floor pit 34. For this purpose, the auxiliary cover plates 76 and 78 are each substantially one-half as wide as the pit 34 and portions of the confronting free edges thereof remote from the margins 44 and 46 are cut away as indicated at 108 and 110, respectively, to receive the parts of the lift installation which would otherwise obstruct their pivotal movement. The recesses 108 and 110 of the auxiliary plates 76 and 78 illustrated are all semicircular to receive the support posts 48, the lift ram 16 and the nonrotating tube 30. When the lift 12 is raised, the confronting semicircular recesses 108 and 110 encircle these various elements of the lift installation.

It may be noted that the auxiliary cover plates 76 and 78 are held in pit covering relationship by the engagement of the cam or bearing members 60 and 62 with the lift ram 16. No other support for the auxiliary cover plates 76 and 78 is needed.

By virtue of the pit cover plate construction of this invention, the floor pit 34 is substantially completely covered at all times by either the main cover plates 36 and 38 or the auxiliary cover plates 76 and 78. The pit 34 is open to some extent only during the brief interval of time in which the lift rail 18 is moving past the cover plates 36 and 38. Of course, at this time the vehicle engaged by the lift 12 is so close to the floor that no one would be near the floor pit 34.

Referring to FIGS. 5-10, another and presently preferred embodiment of a lift installation, generally designated 120, is illustrated therein comprising a vehicle lift, generally designated 122, of the type having a jacking unit including a lift piston or ram 124 movable into and out of a floor pit 126. The lift 122 in FIG. 5 includes a superstructure having an elongate lift beam or rail 128 connected to the top of the lift piston or ram 124 by bolts 130. Projecting upwardly from the rail 128 are a pair of cylindrical supports 132 upon which bolster plates 134 are mounted. Mounted in turn on the bolster plates 134 are pairs of vehicle engaging swing arms 136, only two of which are shown in FIG. 5. The details of mounting of the bolster plates 134 on the vertical supports 132 are unimportant to the instant invention. It may be noted, however, that the bolster plates 134, when lowered as shown in FIG. 7, overlie the side margins, designated 138, of the pit 126 and project a substantial distance inwardly from the end margins 140 ofthe pit 126.

The cover plate construction of the lift installation 120 includes a pair of elongate rectangular main pit cover plates 142 and 144 and a pair of auxiliary cover plates 146 and 148. The main cover plates 142 and 144 are each substantially half as wide as the total width of the floor pit 126 and each substantially as long as the distance between the bolster plates 134. Accordingly, when the lift 122 is lowered, the main cover plates 142 and 144 cover substantially the entire open area of the pit 126 not otherwise covered by the bolster plates 134. When in their pit-covering position, the innermost side margins of the main pit cover plates 142 and 144 are supported by support posts 150 centrally located in the pit 126 on each side of the piston or ram 124.

As in the case of the embodiment of FIGS. 1-4, the auxiliary cover plates 146 and 148 cover substantially the entire open area of the pit 126 when the lift is raised. Accordingly, the auxiliary cover plates 146 and 148 are each substantially as long as the pit 126 and substantially one-half the width of the pit 126. The confronting side margins of the auxiliary cover plates 146 and 148 are cut away as indicated at 152 to receive the piston 124, the support post 150 and a nonrotating tube 154 when the lift is raised.

A novel hinge construction is employed in the embodiment of FIGS. 5-10. Extending the full length of the open end of the pit 126 are a pair of elongate tubes or hinge pins 156 and 158 to which the main and auxiliary cover plates are welded. Referring to FIGS. 8 and 9, the main cover plate 144 and its associated auxiliary cover plate 148 are shown welded to the hinge pin 158. Both the main cover plate 144 and the auxiliary cover plate 148 extend substantially tangentially from the pin 158 and they are located in substantially perpendicular planes, i.e., they lie substantially at with respect to one another. The two cover plates connected to the pin 158 are also interconnected by a pair of braces 160.

The hinge pin 158 is supported by a pair of spaced, upwardly facing angle members or brackets 162 which are welded to the angle member, designated 164, extending along the side margin 138 of the pit 126. In addition, a pair of support blocks or bars 166 welded to the angle members 164 are located at each end of the pit 126 for supporting the extreme ends of the hinge pin 158. The top surfaces of the support members for the hinge pin 158, comprising the angle members 162 and the support blocks 166, are located below the level of the surrounding floor F to appropriately support the hinge pin 158 in a horizontal position with its top surface substantially flush with the level of the surrounding floor F.

The connection of the main cover plate 142 and its associated auxiliary cover plate 146 to the hinge pin 156 is the same as that described in association with the hinge pin 158. Thus as shown in FIGS. 6 and 10, the hinge pin 156 is supported by the top surfaces of angle members or brackets 168 and support blocks or bars 170. The main cover plate 142 is otherwise connected to its associated auxiliary cover plate 146 by braces 172. Both elongate hinge pins 156 and 158 are confined between the opposite sidewalls of the pit 126 by the vertically upright legs of the angle members 168 and 162, respectively, and hence rotate about their longitudinal axes.

Because of the tangential mounting of the main cover plates 142 and 144 on their respective hinge pins 156 and 158, the main cover plates 142 and 144 are substantially flush with the level of the surrounding floor as illustrated in FIG. 10 when the lift 122 is lowered. Because the auxiliary cover plates are also to be substantially flush with the level of upright positions surrounding floor when the lift is raised and because the two pairs of cover plates are mounted at 90 with respect to one another, the main cover plates 142 and 144 must be pivoted through 90 to substantially vertically upright positions when the lift is raised. Accordingly, the main cover plates 142 and 144 further include a pair of lift-engaging cam or bearing members, generally designated 174 and 176, respectively, which project sufficiently from the plane of the faces of the main cover plates 142 and 144 that the main cover plates are moved to vertically uprightpositions when the lift is raised. Referring to FIGS. 6 and 8, the cam or bearing member 176 comprises a roller element 178 having a stub axle 180 rotatably mounted on a yoke formed from a pair of plates 182 welded to the sides of a backing plate 184 having threaded apertures for receiving bolts 186 for attachment to the main cover plate 144. The bearing 176 further includes spacers 188 surrounding the bolts 186 between the backing plate 184 and the inner side of the main cover plate 144. When the cover plates are first installed, the appropriate number and thickness of spacers 188 are inserted upon the bolts 186 to locate the main cover plate 144 in a vertically upright position with the roller element 178 engaged with the raised lift position or ram 124. The construction and assembly of the cam or bearing member 174 is identical to the cam or bearing member 176 and thus further description thereof is unnecessary. Because of this construction, both the auxiliary and the main cover plates pivot through 90 upon the raising and the lowering of the lift 122. When lowered, the auxiliary cover plates 146 and 148 lie closely adjacent the sidewalls of the pit 126 and, therefore, can be accommodated with little or no increase in the width of the pit. The lowered position of the auxiliary cover plate 148 is illustrated by the phantom lines 1480 in FIG. 9.

The construction of H08. -10 embodies certain advantages over that shown in FIGS. l-4. Because of the reduced length of the main cover plates 142 and 144, channel members or other stiffening devices are not required. Preferably, the bolster plates 134 are so located that the wheels of the vehicles to be raised ride over the bolster plates 134 rather than the cover plates 142 and 144. Therefore, the cover plates 142 and 144 can be made from comparatively lightweight metal deck plate or the like.

Because the elongate hinge pins 156 and 158 merely rest upon the angle members and support brackets, the cover plates are simply installed by being lowered into position. Should it become necessary to gain access into the floor pit 126, both pairs of cover plates with their hinge pins 156 and 158, because unconfined against upward movement, can merely be lifted and removed.

Having thus described my invention, 1 claim:

1. In a vehicle lift installation of the type having a floor pit having two opposed side margins extending the length of said floor pit and adapted to receive portions of a lift when lowered which portions project above the floor pit when raised, the improvement comprising a first pair of cover plates covering open areas of said floor pit when the lift is lowered and a second pair of cover plates covering open areas of said floor pit when the lift is raised, each of said second pair of cover plates being substantially half as wide as said floor pit and of the same length as said floor pit.

2. The improvement of claim 1 wherein the confronting edges of said second pair of cover plates have recesses receiving parts of said lift when said lift is raised.

3. The improvement of claim 1 wherein each of said first pair of cover plates are hinged respectively to one and the other of said side margins of said floor pit for pivotal movement about parallel horizontal axes and wherein each of said second pair of cover plates are hinged respectively to said one and said other of said side margins of said floor pit for pivotal movement about spaced parallel axes which are more closely spaced and vertically lower than the said first-mentioned horizontal axes.

4. The improvement of claim 1 wherein one of each of said first pair and said second pair of cover plates are both connected to an elongate hinge pin supported adjacent one of said side margins of said floor pit and wherein the other of said cover plates are both connected to another elongate hinge pin supported adjacent the other of said side margins of said floor pit.

5. ln a vehicle lift installation of the type having vertically movable members located inside a floor pit when the lift is lowered and projecting above fioor level when the lift is raised, a pit cover assembly comprising a first pair of cover plates pivotally mounted adjacent opposed side margins of said floor pit and covering open areas of said floor pit when the lift is lowered, said first pair of cover plates being engaged and pivoted by said vertically movable members when the lift is raised, a second pair of cover plates pivotally mounted adjacent said margins for covering open areas of said floor pit when the lift is raised, and motion transmitting means interconnecting each one of said first pair of cover plates with a different one of said second pair of cover plates whereby said second pair of cover plates is pivoted in response to pivotal movement of said first pair of cover plates.

6. The apparatus of claim 5 wherein said second pair of cover plates comprises plates having confronting edges remote from said margins when in covering relation to said floor pit and wherein portions of said confronting edges are recessed to receive parts of the lift located in said floor pit when said lift is elevated.

7. The apparatus of claim 5 wherein said second pair of cover plates are pivoted about axes offset from the pivot axes of said first pair of cover plates whereupon said second pair of cover plates pivot through different angles than said first pair of cover plates, and wherein said motion transmitting means include ,lost motion connections for accommodating the changes in angular relationship between said plates as they pivot.

8. The apparatus of claim 7 wherein each said motion transmitting means includes a pair of hinge assemblies connected, respectively, to one of said first-pair of cover plates and to one of said second pair of cover plates, each said hinge assembly including a pivotal hinge plate and each said motion-transmitting means further including a pin threadedly connected to one of said pivotal hinge plates and slidable with respect to the other of said pivotal hinge plates.

9. The apparatus of claim 5 wherein said first pair of cover plates are mounted for pivotal movement about a first set of spaced parallel axes and said second pair of cover plates are mounted for pivotal movement about a second set of spaced parallel axes locatedbetween and parallel to said first set of parallel axes.

10. The apparatus of claim 5 wherein said motion transmitting means includes a pair of elongate hinge pins supported respectively adjacent the opposite side margins of said floor pit, one of each of said first pair of cover plates and said second pair of cover plates being connected to one of said hinge pins and the others of said cover plates being connected to the other of said hinge pins.

11. The apparatus of claim 10 wherein said hinge pins are supported adjacent said opposite side margins of said floor pit by support means from which said hinge pins may be raised and removed.

12. A vehicle lift installation including a jacking unit, a superstructure mounted on said jacking unit and a floor pit for receiving at least part of said superstructure when the lift is lowered, said jacking unit including a lift ram centrally located with respect to said floor pit and when elevated projecting vertically therethrough, a first pair of cover plates pivotally mounted on opposite sides of the top of said floor pit for covering open areas'of said floor pit when the lift is lowered, a pair of auxiliary cover plates pivotally mounted to said opposite sides of said floor pit, and motion-transmitting means connecting each of said auxiliary cover plates with the one of said first pair of cover plates pivoted to the same edge of said floor pit, each of said auxiliary cover plates having margins remote from said edges of said floor pit with confronting recessed portions receiving said lift ram when elevated.

13. The apparatus of claim 12 wherein said first-mentioned cover plates have bearing means on the underside thereof engaging said lift ram when said lift is elevated.

14. The apparatus of claim 13 wherein said bearing means projects sufficiently far from the top surface of said first-mentioned cover plates that said first-mentioned cover plates cover plates are oriented in a substantially vertically upright position when said lift is elevated.

15. The apparatus of claim 12 further including a pair of cover plate support posts located on opposite sides of said lift ram for supporting said first-mentioned cover plates when said lift is lowered, said edges of said auxiliary cover plates further having confronting recesses receiving said support posts.

16. The apparatus of claim 15 further including a telescoping nonrotating tube attached to said superstructure and located between said lift ram and one of said support posts with said confronting edges of said auxiliary cover plates further having confronting recesses for receiving said nonrotating tube.

17. The apparatus of claim 12 wherein said first pair of cover plates are mounted for pivotal movement about a first set of spaced parallel axes and said pair of auxiliary cover plates are mounted for pivotal movement about a second set of spaced parallel axes located between and parallel to said first set of parallel axes.

18. The apparatus of claim 12 wherein said motion-transmitting means includes a pair of elongate hinge pins, one of said pair of hinge pins for each of one of said first pair of cover plates and one of said pair of auxiliary cover plates, said hinge pins being connected to said cover plates, and said lift installation further including hinge support means mounted adjacent said opposite sides of the top of said floor pit for supporting said hinge pins along said opposite sides.

19. The apparatus of claim 18 wherein said hinge support means includes a plurality of hinge support members, some for each of said hinge pins, each said support member having an upwardly directed surface upon which said hinge pins lie, and wherein said hinge support means further includes means confining said hinge pin adjacent said side margins of said pit.

20. The apparatus of claim 19 wherein each of said cover plates project substantially tangentially from said elongate hinge pins with each said first pair of cover plates lying in a plane substantially perpendicular to the associated said auxiliary cover plate connected to the same hinge pin.

21. ln a vehicle lift installation of the type having a vertically movable lift ram and a superstructure at least partially located inside a floor pit when the lift is lowered and projecting above floor level when the lift is raised, a pit cover assembly comprising a first pair of cover plates pivotally mounted adjacent opposite margins of said floor pit, each adapted to occupy a first, lowered position generally in the plane of the top of the floor pit and covering open areas of the floor pit when the lift is lowered and a second, raised position resting against the lift ram, said first pair of cover plates being pivotally moved from said first position to said second position by engagement of said superstructure therewith, a second pair of cover plates pivotally mounted adjacent said upper margins of said pit, each occupying a first position when the lift is lowered beneath said first pair of cover plates and extending generally vertically in said floor pit, each said second pair of cover plates being pivotally movable to a second position substantially fiush with the level of the floor surrounding said pit and in covering relation to otherwise open areas thereof, and motion-transmitting means interconnecting said first and second pairs of cover plates whereby said second pair of cover plates is pivoted in response to pivotal movement of said first pair of cover plates 22. The apparatus of claim 21 wherein said second pair of cover plates comprises plates having confronting edges remote from said margins when in covering relation to said floor pit and wherein portions of said confronting edges are recessed to receive parts of the lift located in said floor pit when said lift is elevated.

23. The apparatus of claim 21 wherein said first pair of cover plates are mounted for pivotal movement about a first set of spaced parallel axes and said second pair of cover plates are mounted for pivotal movement about a second set of spaced parallel axes located between and parallel to said first set of parallel axes.

.24. The apparatus of claim 21 wherein each of said second pair of cover plates are pivoted about axes offset from the pivot axes of said first pair of cover plates whereupon said second pair of cover plates pivot through different angles than said first pair of cover plates, and wherein said motion-transmitting means include lost motion connections for accommodating the changes in angular relationship between said plates as they pivot.

25. The improvement of claim 24 wherein each said motion-transmitting means includes a pair of hinge assemblies connected respectively to one of said first pair of cover plates and to one of said second pair of cover plates, each said hinge assembly including a pivotal hinge plate and each said motion transmitting means further including a pin threadedly connected to one of said pivotal hinge plates and slidable with respect to the other of said pivotal hinge plates 26. The apparatus of claim 21 wherein one of each of said first pair of cover plates and said second pair of cover plates are connected to a first elongate hinge pin, the othersof saidcover plates being connected to a second elongate hinge pin, and further including hinge support means located along said opposite margins of said floor pit for supporting said first and second hinge pins for rotation about spaced parallel axes.

27. The apparatus of claim 26 wherein each of said first pair of cover plates has bearing means adapted to en age said lift ram when raised and projecting sufficiently far mm the sur- I when said lift is raised.

UNITEE STATES PATENT oFFisE QERTIFICATE 0F QOREQTION Patent No. 3,6O8 6'75 Dated September 28, 1971 Inventor(s) Martin J. Sherry It is cerhfied that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 6, line &2, after "(:f delete --upright positions-- Col. 6, line &3 insert --the-- at beginning of line (301. 6, line 52, "uprightpositions" should be ---uprig-t positions--- Col. 6, line 65 "pc-si610m shoulcl be --piston- Col. 8, line 51 delete "cover plates" Sligned and sealefi this 23rd day of May 191 2.

{SEAL} Attest:

EDWARD MELBTGHER, JRa ROBERT GOTTSCHALK i Masa -1n" Officer Commissioner of Patents 

1. In a vehicle lift installation of the type having a floor pit having two opposed side margins extending the length of said floor pit and adapted to receive portions of a lift when lowered which portions project above the floor pit when raised, the improvement comprising a first pair of cover plates covering open areas of said floor pit when the lift is lowered and a second pair of cover plates covering open areas of said floor pit when the lift is raised, each of said second pair of cover plates being substantially half as wide as said floor pit and of the same length as said floor pit.
 2. The improvement of claim 1 wherein the confronting edges of said second pair of cover plates have recesses receiving parts of said lift when said lift is raised.
 3. The improvement of claim 1 wherein each of said first pair of cover plates are hinged respectively to one and the other of said side margins of said floor pit for pivotal movement about parallel horizontal axes and wherein each of said second pair of cover plates are hinged respectively to said one and said other of said side margins of said floor pit for pivotal movement about spaced parallel axes which are more closely spaced and vertically lower than the said first-mentioned horizontal axes.
 4. The improvement of claim 1 wherein one of each of said first pair and said second pair of cover plates are both connected to an elongate hinge pin supported adjacent one of said side margins of said floor pit and wherein the other of said cover plates are both connected to another elongate hinge pin supported adjacent the other of said side margins of said floor pit.
 5. In a vehicle lift installation of the type having vertically movable members located inside a floor pit when the lift is lowered and projecting above floor level when the lift is raised, a pit cover assembly comprising a first pair of cover plates pivotally mounted adjacent opposed side margins of said floor pit and covering open areas of said floor pit when the lift is lowered, said first pair of cover plates being engaged and pivoted by said vertically movable members when the lift is raised, a second pair of cover plates pivotally mounted adjacent said margins for covering open areas of said floor pit when the lift is raised, and motion transmitting means interconnecting each one of said first pair of cover plates with a different one of said second pair of cover plates whereby said second pair of cover plates is pivoted in response to pivotal movement of said first pair of cover plates.
 6. The apparatus of claim 5 wherein said second pair of cover plates comprises plates having confronting edges remote from said margins when in covering relation to said floor pit and wherein portions of said confronting edges are recessed to receive parts of the lift located in said floor pit when said lift is elevated.
 7. The apparatus of claim 5 wherein said second pair of cover plates are pivoted about axes offset from the pivot axes of said first pair of cover plates whereupon said second pair of cover plates pivot through different angles than said first pair of coveR plates, and wherein said motion transmitting means include lost motion connections for accommodating the changes in angular relationship between said plates as they pivot.
 8. The apparatus of claim 7 wherein each said motion transmitting means includes a pair of hinge assemblies connected, respectively, to one of said first pair of cover plates and to one of said second pair of cover plates, each said hinge assembly including a pivotal hinge plate and each said motion-transmitting means further including a pin threadedly connected to one of said pivotal hinge plates and slidable with respect to the other of said pivotal hinge plates.
 9. The apparatus of claim 5 wherein said first pair of cover plates are mounted for pivotal movement about a first set of spaced parallel axes and said second pair of cover plates are mounted for pivotal movement about a second set of spaced parallel axes located between and parallel to said first set of parallel axes.
 10. The apparatus of claim 5 wherein said motion transmitting means includes a pair of elongate hinge pins supported respectively adjacent the opposite side margins of said floor pit, one of each of said first pair of cover plates and said second pair of cover plates being connected to one of said hinge pins and the others of said cover plates being connected to the other of said hinge pins.
 11. The apparatus of claim 10 wherein said hinge pins are supported adjacent said opposite side margins of said floor pit by support means from which said hinge pins may be raised and removed.
 12. A vehicle lift installation including a jacking unit, a superstructure mounted on said jacking unit and a floor pit for receiving at least part of said superstructure when the lift is lowered, said jacking unit including a lift ram centrally located with respect to said floor pit and when elevated projecting vertically therethrough, a first pair of cover plates pivotally mounted on opposite sides of the top of said floor pit for covering open areas of said floor pit when the lift is lowered, a pair of auxiliary cover plates pivotally mounted to said opposite sides of said floor pit, and motion-transmitting means connecting each of said auxiliary cover plates with the one of said first pair of cover plates pivoted to the same edge of said floor pit, each of said auxiliary cover plates having margins remote from said edges of said floor pit with confronting recessed portions receiving said lift ram when elevated.
 13. The apparatus of claim 12 wherein said first-mentioned cover plates have bearing means on the underside thereof engaging said lift ram when said lift is elevated.
 14. The apparatus of claim 13 wherein said bearing means projects sufficiently far from the top surface of said first-mentioned cover plates that said first-mentioned cover plates cover plates are oriented in a substantially vertically upright position when said lift is elevated.
 15. The apparatus of claim 12 further including a pair of cover plate support posts located on opposite sides of said lift ram for supporting said first-mentioned cover plates when said lift is lowered, said edges of said auxiliary cover plates further having confronting recesses receiving said support posts.
 16. The apparatus of claim 15 further including a telescoping nonrotating tube attached to said superstructure and located between said lift ram and one of said support posts with said confronting edges of said auxiliary cover plates further having confronting recesses for receiving said nonrotating tube.
 17. The apparatus of claim 12 wherein said first pair of cover plates are mounted for pivotal movement about a first set of spaced parallel axes and said pair of auxiliary cover plates are mounted for pivotal movement about a second set of spaced parallel axes located between and parallel to said first set of parallel axes.
 18. The apparatus of claim 12 wherein said motion-transmitting means includes a pair of elongate hinge pins, one of said pair of hinge Pins for each of one of said first pair of cover plates and one of said pair of auxiliary cover plates, said hinge pins being connected to said cover plates, and said lift installation further including hinge support means mounted adjacent said opposite sides of the top of said floor pit for supporting said hinge pins along said opposite sides.
 19. The apparatus of claim 18 wherein said hinge support means includes a plurality of hinge support members, some for each of said hinge pins, each said support member having an upwardly directed surface upon which said hinge pins lie, and wherein said hinge support means further includes means confining said hinge pin adjacent said side margins of said pit.
 20. The apparatus of claim 19 wherein each of said cover plates project substantially tangentially from said elongate hinge pins with each said first pair of cover plates lying in a plane substantially perpendicular to the associated said auxiliary cover plate connected to the same hinge pin.
 21. In a vehicle lift installation of the type having a vertically movable lift ram and a superstructure at least partially located inside a floor pit when the lift is lowered and projecting above floor level when the lift is raised, a pit cover assembly comprising a first pair of cover plates pivotally mounted adjacent opposite margins of said floor pit, each adapted to occupy a first, lowered position generally in the plane of the top of the floor pit and covering open areas of the floor pit when the lift is lowered and a second, raised position resting against the lift ram, said first pair of cover plates being pivotally moved from said first position to said second position by engagement of said superstructure therewith, a second pair of cover plates pivotally mounted adjacent said upper margins of said pit, each occupying a first position when the lift is lowered beneath said first pair of cover plates and extending generally vertically in said floor pit, each said second pair of cover plates being pivotally movable to a second position substantially flush with the level of the floor surrounding said pit and in covering relation to otherwise open areas thereof, and motion-transmitting means interconnecting said first and second pairs of cover plates whereby said second pair of cover plates is pivoted in response to pivotal movement of said first pair of cover plates.
 22. The apparatus of claim 21 wherein said second pair of cover plates comprises plates having confronting edges remote from said margins when in covering relation to said floor pit and wherein portions of said confronting edges are recessed to receive parts of the lift located in said floor pit when said lift is elevated.
 23. The apparatus of claim 21 wherein said first pair of cover plates are mounted for pivotal movement about a first set of spaced parallel axes and said second pair of cover plates are mounted for pivotal movement about a second set of spaced parallel axes located between and parallel to said first set of parallel axes.
 24. The apparatus of claim 21 wherein each of said second pair of cover plates are pivoted about axes offset from the pivot axes of said first pair of cover plates whereupon said second pair of cover plates pivot through different angles than said first pair of cover plates, and wherein said motion-transmitting means include lost motion connections for accommodating the changes in angular relationship between said plates as they pivot.
 25. The improvement of claim 24 wherein each said motion-transmitting means includes a pair of hinge assemblies connected respectively to one of said first pair of cover plates and to one of said second pair of cover plates, each said hinge assembly including a pivotal hinge plate and each said motion transmitting means further including a pin threadedly connected to one of said pivotal hinge plates and slidable with respect to the other of said pivotal hinge plates.
 26. The apparatus of claim 21 wherein one of each of Said first pair of cover plates and said second pair of cover plates are connected to a first elongate hinge pin, the others of said cover plates being connected to a second elongate hinge pin, and further including hinge support means located along said opposite margins of said floor pit for supporting said first and second hinge pins for rotation about spaced parallel axes.
 27. The apparatus of claim 26 wherein each of said first pair of cover plates has bearing means adapted to engage said lift ram when raised and projecting sufficiently far from the surfaces of said first pair of cover plates that said first pair of cover plates are located in substantially vertical positions when said lift is raised. 